This invention relates generally to the art of electrical connectors, and, more particularly, to a female or socket terminal for an electrical connector.
Mating electrical connectors typically employ pairs of inter-engaging pin arid socket terminals for interconnecting a plurality of circuits or wires 117 through the mated connectors. The pin and socket terminals are often called male and female terminals.
One type of female terminal includes a generally rectangular socket or receptacle at its mating end for receiving a generally rectangular pin or male terminal therein. The mating end is formed by an elongate body defining top and bottom walls and spaced apart opposing sidewalls, thereby defining a passageway for receiving the male terminal. Such terminals are conventionally stamped and formed from sheet material and the top and bottom walls may have open seams or slits, whereby the opposing sidewalls can flex transversely to the longitudinal axis of the terminal to enlarge the passageway as the male terminal is inserted therein.
Many applications require that connectors equipped with these types of terminals be plugged or mated together while electrical power is present at the terminals. Such connectors are known as hot plugable connectors. During mating, and primarily unmating of the terminals in these hot plugable connectors, electrical arcs are created by electrical current passing through the terminals as the terminals are mated or unmated. The terminals may become damaged by such arcing. Furthermore, non-conductive or poorly conducting residues, such as carbon and the like, may build up on the electrical contacts in the terminals due to the arcing. Such residues can interfere with the quality of the electrical contact between the terminals in a subsequent connection.
Some attempts to provide protection against arc discharging in the prior art include providing separate sequential terminals, or providing forward or lateral extensions on the terminals for sequential engagement of the terminals. While effective in reducing the negative effects of arcing, such terminals were larger than necessary due to the extra space required by these forward or lateral extensions. In some cases, these modified terminals were also more complicated to manufacture.
This invention is directed to solving the problems identified above and to satisfying the need for an improved elongated female electrical terminal that has provision for arc discharge.
An object of the present invention is therefore to provide a new and improved female electrical terminal of the character described.
Another object of the present invention is to provide a means of discharging any arcs between terminals as connectors are hot plugged together.0
A further object of the present invention is to provide one or more sacrificial electrical contacts in a female terminal for engaging the male terminal to discharge any arcs before the male terminal engages the primary electrical contacts.
Yet another object of the present invention is to provide one or more sacrificial contacts in the female terminal that establish and continue electrical contact with a male terminal before initial engagement of one or more primary electrical contacts by the male terminal.
A still further object of the present invention is to provide one or more sacrificial contacts to discharge arcing between male and female terminals by disposing the sacrificial contacts forwardly of the primary contacts in the mating passageway of the female terminal.
Another object of the present invention is to provide a sacrificial contact in the mating passageway of the female terminal in the form of an elongated bar that projects into the passageway to contact the male terminal prior to the male terminal contacting any primary contact.
Yet another object of the present invention is to provide a female terminal, with arc discharge protection for the primary contacts, which is compact and inexpensive to manufacture.
In the exemplary embodiment of the invention, a female terminal has a mating end to receive a male pin with spaced apart flat surfaces and a circuit connecting end for connection to a wire, or the like. The elongate body of the female terminal defines a terminal-receiving passageway with two spaced apart sidewalls extending lengthwise along the passageway. One or more primary terminal contacts are disposed inwardly from at least one of the sidewalls into the terminal-receiving passageway to provide the electrical contact between the female and male terminals when the male terminal is fully inserted into the female terminal. These primary contacts make be of any form or shape, such as dimples formed in the sidewalls of the female terminal. However, these primary terminal contacts are preferably in the form of flat contacting surfaces formed in the opposing sidewalls, and that are disposed at an angle to the sidewalls.
According to one aspect of the present invention, these sacrificial contacts are disposed forwardly of the primary contacts such that the male terminal, when inserted into the passageway will come into contact with the sacrificial contacts before coming into contact with the primary contacts. The sacrificial contacts may be elongated in the direction of insertion of the male terminal into the passageway of the female terminal and have a curved or arcuate surface portion that projects inwardly into the passageway for contacting the male terminal, with apertures separating the elongated sacrificial contacts from the mating end of the female terminal. For example, the portion of the sacrificial contacts that are curved may be spherical in shape.
The sidewalls are resilient and flex apart from each other as the male terminal is inserted in the passageway between the sidewalls and come into engagement with the sacrificial contacts. As the male pin is inserted further into the passageway and engages the primary electrical contacts, the sidewalls continue to flex and separate along an axis generally parallel to their respective sidewalls and in a direction perpendicular to the passageway. Preferably, the primary contacts are in the form of angled and flat contacting surfaces defined in the sidewalls that become generally coplanar with the flat surfaces of the male pin as the sidewalls separate during insertion of the male terminal for improved surface-to-surface contact over substantially entire area of the flat contacting surfaces. The resilient sidewalls then apply normal forces at the flat contacting surfaces against the male pin for improved electrical contact, both with the primary electrical contacts and with the sacrificial contacts.
One or more notches or cuts may be defined in the sidewalls or in the generally U-shaped channels to control or to improve the flexing of the sidewalls when the male pin is inserted into the passageway. Such notches may also better define the bending axis of each sidewall, including control over the flexibility of each sidewall, the normal forces exerted by primary contacts and the sacrificial contacts of the female terminal against the male pin, and the like. These notches will further define the degree of resiliency of the U-shaped channels.